1. Field of the Invention
The present invention relates to a technology for reducing network traffic in a content delivery network, and more particularly, to an adaptive cache transformation architecture for caches deployed forward to minimize duplicated transmission, by automatically storing content in a subscriber network area.
2. Discussion of Related Art
In recent years, as smart phones having an improved performance are widely spread and content providers are rapidly increased based on the proliferation of smart phones, traffic of mobile communication networks is in the trend of getting increased. Therefore, speeds of web download and transmission of content, such as video, audio, image, and application are degraded and thus QoS is emerging as an issue
In particular, with the development of content transmission technologies, a large capacity of file transmission becomes feasible in the online video services, such as Video On Demand (VOD) and Live Streaming, music streaming, file upload and file download, and accordingly, various services to transmit a large capacity of content are also provided.
However, in general, these content providing services have a tendency to provide duplicate content to a user in the same domain or the same wireless coverage in a varied frequency of duplicated transmissions though depending on the popularity, and according to the increasing use of the content providing services, such duplicate content occupies more and more portion of the network traffic.
The transmission of duplicate content further increases the traffic load of a communication network, and thus there has been an effort to reduce traffic by preventing the duplicated transmission, providing Contents Delivery network (CDN) services as a relevant technology. The CDN service is provided to stably deliver to user various pieces of content including video, such as movies and music video. In general, the CND service is implemented by storing pieces of content in a plurality of local caching devices deployed on a network in a distributed manner, and selecting the optimum cache server among a plurality of local cache servers through a load distribution device, such as a global load balance (GLB) server such that a requested content is transmitted to a terminal of a user through the selected cache server.
The CDN is implemented to reduce the instability issues occurring on the Internet, such as data loss, bottle neck, low transmission speed and data latency, based on the Internet network.
In the CDN service, the content caching technology is provided to selectively cache content in a plurality of local caching devices deployed on the network in a distributed manner. Such content caching needs to be performed in consideration of the size of a storage space of the local caching devices. In addition, there is a need to consider the time taken to determine whether content requested by a user matches cached content, and consider a cache hit rate that represents a percentage by which content requested by a user matches cached content.
In particular, as the paradigm of using a network has been shifted to focus on content, numerous studies have been conducted on the content centric transmission network worldwide. However, currently, the content delivery network market has been established based on the global network equipment companies and the Internet service providers, and thus only a few studies have been undertaken on a method of reducing network traffic through content analysis.
In addition, since the video content traffic is occupied by duplicated content, there is a need of a systematic traffic management plan through a software platform other than through network expansion.